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Transcript of ICTP
Oscillatons as Galactic Dark Matter Halos
Tonatiuh Matoshttp:/www.fis.cinvestav.mx/~tmatos
• Inflation• +• Scalar Field DM
(SFDM)• +• Dark Energy
Cosmology
+
Galaxies Formation
=
• The model consists of
The Model comes from• Examples:• Braneword Scenario• Superstrings • Contains an effective SF potential:
• V f1exp() + f2exp(-) + …
• • V = V0[cosh() – 1]
• H2 = 8/(3Mpl2) (1 + /b)
• Inflation graceful exit• BBN Cosmology • Fix the free constants.
The CosmologyT. Matos and L. Ureña, Class. Q. Grav. 17(2000)L75
• SFDM with the SF potential:• V = V0[cosh() –1]• Dark Energy:
• +
• Baryons, Neutrinos, etc.
0.23 0.73b 0.04
Scalar Field Fluctuations
T. Matos and L. Ureña, Phys. Rev. D63(2001)063506
The linear fluctuations of the SFDM model follow the
CDM ones
Natural Cut-off
The linear fluctuations contain a natural cut-of in the mass power spectrum. Thus, this model has no problems with
the production of substructure.
THE SCALAR FIELD DARK MATTER MODEL
• It is an alternative model to CDM• SFDM model is insensitive to initial conditions • Behaves as CDM at cosmological scales• Reproduces all the successes CDM above
galactic scales.• Predicts a sharp cut-off in the mass power
spectrum • The favored values for the two free parameters 20 V0 (310-27 Mpl )4 m 10-23 eV
Scalar Field Fluctuation = Oscillaton = Galaxy Halo
Tonatiuh Matos and F. Siddhartha Guzman Class. Q. Grav. 17(2000)L9; T. Matos, F. S. Guzman and D. Nuñez, Phys. Rev. D62(2000)061301(R);Tonatiuh Matos and F. Siddhartha Guzman, Class.Q. Grav. 18(2001)5055
The critical mass of oscillatons collapse is
• Mcrit 0.1 M2Planck /m
• If m 10-23 eV 20
• Mcrit 1012 M¯ ~ Galaxy halo
Galaxy virialization
• The oscillatons virialize in a very short time. In this figure it is shown the rate of kinetic energy K and potential energy |W| of the scalar field fluctuation. It goes very fast to ½.
Density Profiles
Here we show the comparison between the NFW, Isothemal and the SFDM density
profiles for galaxies.
Density Profiles
Density Profiles
LSB Galaxies
Density Profiles
LSB Galaxies
Conclusion
• The scalar field is a good candidate to be the Dark Matter
of the Universe